News

Protalex Doses First Patient in Final and Highest Dose Cohort of European Phase 1b Study of PRTX-100 in Immune Thrombocytopenia

U.S. 202 ITP Study to Expand Enrollment with Opening of Sites in U.K.

FLORHAM PARK, N.J.--(BUSINESS WIRE)--
Protalex, Inc. (OTCQB: PRTX), a clinical-stage biopharmaceutical
company, today announced that following a planned interim analysis of
data from the fourth dose cohort of its European Phase 1b study of
PRTX-100 (PRTX-100-203 Study) in adults with persistent/chronic Immune
Thrombocytopenia (ITP), the Company has initiated enrollment in the
fifth and highest dose cohort of this dose-escalating study. The first
patient in this final cohort was recently dosed in the United Kingdom at
24 micrograms/kg, the highest dose of PRTX-100 used in any clinical
trial to date. One of the three patients treated in the fourth dose
cohort (18 micrograms/kg) achieved a protocol defined platelet response.
PRTX-100 has been granted Orphan Drug Designation in the U.S. and in
Europe for the treatment of ITP.

The 203 Study is a European open-label, dose escalating study that can
enroll up to 30 patients in as many as five cohorts. Patients with
chronic, persistent ITP are eligible for the 203 Study if they have
received one prior ITP treatment and their platelet counts remain low.
Each patient receives four weekly intravenous doses of PRTX-100 and is
monitored for up to 48 weeks thereafter. The primary study endpoint of
the 203 Study is to evaluate the safety of PRTX-100. Secondary endpoints
include efficacy, immunogenicity, and pharmacokinetics.

“We are very pleased to be treating patients in the final and highest
dose cohort of the 203 Study in Europe, particularly as one patient from
the fourth cohort demonstrated a platelet response to treatment with
PRTX-100. Platelet responses have been observed in patients treated with
lower doses of PRTX-100, so we look forward to the treatment results in
the fifth and highest dose cohort,” stated Richard J. Francovitch,
Ph.D., Protalex’s Vice President, ITP Programs. “We have been satisfied
with the safety data obtained from patients treated in lower dose
cohorts and expect the results from this final dose cohort will provide
important safety data relating to the highest dose of PRTX-100 yet
studied in clinical trials. Importantly, the collective data from the
203 Study will inform the future development plans for the ITP program.”

Arnold P. Kling, President, of Protalex, commented, “Protalex is
encouraged by the increased rate of enrollment into the 203 Study since
opening the trial at multiple sites in the U.K. We were able to initiate
enrollment in the final dose cohort within 2 months of opening the last
cohort. With that in mind, we have received regulatory approval in the
U.K. to open enrollment in our Phase 1/2 study of PRTX-100 in adults
with persistent/chronic ITP (PRTX-100-202 Study) that previously was
only open at sites in the U.S. Several new clinical sites in the U.K.
will begin recruiting patients in the coming weeks for the fourth cohort
of the 202 Study at a dose of 12.0 micrograms/kg.

The 202 Study is an open-label, dose escalating study that can enroll up
to 36 patients in as many as six cohorts. Each patient receives four
weekly intravenous doses of PRTX-100 and is monitored for up to 48 weeks
thereafter. The primary study endpoint of the 202 Study is a platelet
response to PRTX 100. Secondary endpoints include safety,
immunogenicity, and pharmacokinetics. Enrollment is continuing at
several study sites in the U.S.

About Immune Thrombocytopenia (ITP)

ITP is an autoimmune condition characterized by bruising and increased
bleeding due to immune-mediated accelerated destruction of platelets and
impaired production of platelets. The diagnosis of ITP is based upon a
low platelet count, usually less than 100,000 per microliter of blood,
in the absence of other possible causes of reduced platelet numbers such
as an underlying illness or medication.

About PRTX-100

PRTX-100, a new generation immunomodulatory therapy, is a highly
purified form of SpA, an immunomodulatory protein known to modify
aspects of the human immune system. PRTX-100 has the ability, at very
low concentrations, to bind to human B-lymphocytes and macrophages and
to modulate immune processes. Pre-clinical data indicate that PRTX-100
may have the potential to treat ITP by reducing the immune-mediated
destruction of the platelets. The two most recently approved drugs used
to treat ITP, Nplate® (romiplostin) and Promacta®/Revolade™
(eltrombopag) both increase the production of platelets but do not
appear to affect the underlying platelet destruction process. The
safety, tolerability, and pharmacokinetics of PRTX-100 have been
characterized in six clinical studies, and PRTX-100 has been granted
Orphan Drug Designation in the U.S. and Europe for the treatment of ITP.
In two Phase 1b clinical trials in adult patients with active Rheumatoid
Arthritis (RA), PRTX-100 was generally safe and well tolerated at all
dose levels, and at certain higher doses, more patients showed
improvement in measures of RA disease activity than did patients at the
lower dose or placebo cohorts. PRTX-100 is given as a short intravenous
infusion.

Nplate® is a registered trademark of Amgen, Inc. and Promacta®/Revolade™
are registered trademarks of Novartis AG.

About Protalex, Inc.

Protalex, Inc. is a clinical-stage biopharmaceutical company focused on
the development of a class of drugs for treating autoimmune and
inflammatory diseases including RA and Immune Thrombocytopenia (ITP). In
the U.S., Protalex has open INDs for the treatment of RA and ITP and in
Europe, an open IMPD for ITP. Please visit the Protalex website at www.protalex.com
to learn more about Protalex and its lead drug candidate, PRTX-100.

Forward-Looking Statements

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or current fact constitute "forward-looking statements." Such
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forward-looking statements contained herein are also subject generally
to other risks and uncertainties that are described from time to time in
the Company's filings with Securities and Exchange Commission.